<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>jade example</title>
    <style>
      div
      {width:100px;height:100px;background:#ccc;text-align:center;line-height:100px;float:left;margin:10px auto}
      div.last {clear:left}
    </style>
    <body>
      <div>0</div>
      <div>1</div>
      <div>2</div>
      <div>3</div>
      <div class="last">4</div>
      <div>5</div>
      <div>6</div>
      <div>7</div>
      <div class="last">8</div>
      <div>9</div>
      <div>10</div>
      <div>11</div>
    </body>
  </head>
</html>